I have a 68 Camaro 396. The heads have been redone with no portwork or anything like that, just new valves, factory size springs, etc. The block had been bored .30 I have a set of roller rockers and roller lifters for it and planned to run the comp cam 11-432-8 from summit racing. Can I run the factory size pushrods with the roller lifters and rockers and how can I tell ? I also have a performer 2.0 intake, Holley 600 cfm carb and flowtech blockhugger headers. How much power do you think this set-up will get me ? The factory engine was rated at 350 hp but I hear these figures are under rated... If that is true ? Any help on the pushrods would be great.

let me get home and run some numbers

On my rockers the say 1.7 7/16 and the lifters are the Crower 66201-16 sold from summit racing.

There is a 12 dollar plastic tool that you can use to see if you are close. Its not as accurate as a actual pushrod measuring tool but it is cheaper. If the valves are stock length its safe to get stock pushrods. Rockers wont make a difference. Sorry Im not good with HP estimates.

The chances on your stock pushrods being right are pretty close to zero. You should always verify correct pushrod length-get a set of adjustable pushrods and measure length with everything adjusted correctly. The pushrods are the last thing to go in the engine when you assemble. Not only will milling the deck or cylinder heads, but head gasket thickness, aftermarket heads, and even different cams can affect it. Every engine I build ends up with a different length pushrod to get the right geometry. Comp Cams has adjustable pushrods for measuring.

Nice advice. Thank you. I will see if the guy doing my engine build has the correct tool to measure it. I was just trying to get all the parts ordered at once, But I guess I will have to order the pushrods once we get the heads bolted down.

the wrong pushrods will be a verybad thing...very bad indeed...

375 if my math is correct.

I ran your setup on Desktop Dyno and with Stock Canted Oval Port heads with 2.19/1.88 valves, @ 9:1 compression ratio, .030 over bore making it a 402 now, and your roller cam and your small tube headers with mufflers and that itty bitty 600 CFM carb with a Performer dual plane manifold, it still could possibly make 434 HP @ 5000 RPM and 462 lb/ft Torque @4500 RPM. With a 750 carb (personally I wouldn't run anything less than a 750 on a big block, IMHO) and you jump to 446 HP @ 5500 RPM and 470 lb/ft Torque at 4500 RPM. A 12 HP gain from just a little more carb. Not too Shabby!

I ran your setup on Desktop Dyno and with Stock Canted Oval Port heads with 2.19/1.88 valves, @ 9:1 compression ratio, .030 over bore making it a 402 now, and your roller cam and your small tube headers with mufflers and that itty bitty 600 CFM carb with a Performer dual plane manifold, it still could possibly make 434 HP @ 5000 RPM and 462 lb/ft Torque @4500 RPM. With a 750 carb (personally I wouldn't run anything less than a 750 on a big block, IMHO) and you jump to 446 HP @ 5500 RPM and 470 lb/ft Torque at 4500 RPM. A 12 HP gain from just a little more carb. Not too Shabby!


Sounds great ! I will be buying the 750 carb then. Cant wait to get this thing back together. Thanks for the test results you have !

Pushrods is always the last thing you get, always waiting on pushrods. Stinkin pushrods. I had to wait 2 friggin weeks on Comp for pushrods here a couple engines ago and it about killed me waiting. Manton was pretty quick on my last wait, 3 days I think.

Yeah get a little more carb.

I bought a holley 750 carb. I hope to get the heads bolted on sometime this week/weekend. Still gotta get the tool to measure the pushrod length though. Thanks for all the help !

Comp makes this rocker/pushrod kit for your cam:
http://store.summitracing.com/partdetail.asp?part=CCA-RPR205
Also make sure your springs are compatible with this much lift. Sometimes stock BBC springs don't like more that .450-.475".